scholarly journals Preparation of Polystyrene Microsphere-Templated Porous Monolith for Wastewater Filtration

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7165
Author(s):  
Nur Faezah Ibadat ◽  
Suryani Saallah ◽  
Clarence M. Ongkudon ◽  
Mailin Misson
Keyword(s):  
Physicochemical Characteristics ◽  
High Permeability ◽  
Solvent Treatment ◽  
Polystyrene Microsphere ◽  
Template Removal ◽  
Monomer Ratio ◽  
Dead End ◽  
Porous Monolith ◽  
Wastewater Filtration ◽  
Quality Assessments

Porous monoliths prepared using templates are highly sought after for filtration applications due to their good mass transport properties and high permeability. Current templates, however, often lead to the formation of dead-end pores and irregular pore distributions, which reduce the efficiency of the substrate flow across the monolith column. This study focused on the preparation of a microsphere-templated porous monolith for wastewater filtration. The optimal template/monomer ratio (50:50, 60:40, 70:30) was determined, and appropriate template removal techniques were assessed for the formation of homogenous pores. The physicochemical characteristics and pore homogeneity of the monoliths were examined. The 60:40 ratio was determined to result in monoliths with homogeneous pore distributions ranging from 1.9 μm to 2.3 μm. SEM and FTIR investigations revealed that solvent treatment was effective for removing templates from the resulting solid monolith. The water quality assessments revealed reductions in the turbidity and the total number of suspended particles in the tested wastewater of up to 96–99%. The findings of this study provide insightful knowledge regarding the fabrication of monoliths with homogenous pores that are beneficial for wastewater treatment.

Properties and Filtration Performance of Porous Clay Membrane Produced Using Sawdust as Pore Forming Agent

2019 ◽  
Vol 821 ◽  
pp. 337-342 ◽  
Author(s):  
Che Zulkifli Rumaizah ◽  
Azaman Fazureen ◽  
Razali Mohd Hasmizam ◽  
Ali Asmadi ◽  
Muhamad Nor Mohd Al Amin
Keyword(s):  
Ceramic Membrane ◽  
High Permeability ◽  
Optimum Amount ◽  
Batch Mode ◽  
Turbidity Removal ◽  
Dead End ◽  
Wastewater Filtration ◽  
High Turbidity ◽  
Aquaculture Wastewater ◽  
Clay Membrane

This study investigated the effect of sawdust at 0, 10, 20, 30 and 40 wt% towards physical properties and filtration efficiency of porous clay membrane. Sawdust in various quantities was added into water containing clay, polyethylene glycol and sodium silicate and then stirred to form homogenized slurry. The slurry then was casted into Plaster of Paris (PoP) mould. The green body was cut into required sizes, dried and sintered in furnace at 1000 °C. The porosity and density of porous clay was determined by Archimedes principle, while morphology was observed by Hitachi Tabletop Scanning Electron Microscope (TTSEM). The filtration test was examined on a dead-end filtration setup in batch mode operation using nitrogen as carrier gas. Distilled water was filtered and used to determine membrane permeability, while aquaculture wastewater filtration was used to determine the turbidity removal. Turbidity of aquaculture wastewater and effluent (after filtration) were measured using turbidity meter. The results indicated that porosity increased from 38 % to 64 %, while density decreased from 1.5 g/cm3 to 0.8 g/cm3 with increasing amount of sawdust from 0 to 40 wt%. This data was supported by TTSEM which is indicate that the amount of pores increased with increasing amount of sawdust. Permeation of membrane increased from 45289 to 143999 L.h-1.m-2.bar-1 and efficiency of turbidity removal increased from 87 % to 89 % with increasing amount of sawdust from 0 to 40 wt%. As conclusion, 30 wt% was an optimum amount of sawdust which is produced ceramic membrane with good structure integrity, porosity, high permeability and high turbidity removal.

Applications of SEM/EDXA in cement clinker investigation

1990 ◽  
Vol 48 (4) ◽  
pp. 870-871
Author(s):  
Arezki Tagnit-Hamou ◽  
Shondeep L. Sarkar
Keyword(s):  
Mineralogical Composition ◽  
Physicochemical Characteristics ◽  
Cement Clinker ◽  
Accurate Information ◽  
Phase Identification ◽  
History Of ◽  
Bulk Chemical ◽  
Resolution Imaging ◽  
Proven Method ◽  
Instantaneous Chemical

All the desired properties of cement primarily depend on the physicochemical characteristics of clinker from which the cement is produced. The mineralogical composition of the clinker forms the most important parameter influencing these properties.Optical microscopy provides reasonably accurate information pertaining to the thermal history of the clinker, while XRDA still remains the proven method of phase identification, and bulk chemical composition of the clinker can be readily obtained from XRFA. Nevertheless, all these microanalytical techniques are somewhat limited in their applications, and SEM/EDXA combination fills this gap uniquely by virtue of its high resolution imaging capability and possibility of instantaneous chemical analysis of individual phases.Inhomogeneities and impurities in the raw meal, influence of kiln conditions such as sintering and cooling rate being directly related to the microstructure can be effectively determined by SEM/EDXA. In addition, several physical characteristics of cement, such as rhcology, grindability and hydraulicity also depend on the clinker microstructure.

Common modifications of selenocysteine in selenoproteins

2019 ◽  
Vol 64 (1) ◽  
pp. 45-53 ◽  
Author(s):  
Elias S.J. Arnér
Keyword(s):  
Amino Acids ◽  
Covalent Binding ◽  
Physicochemical Characteristics ◽  
Redox Active

Abstract Selenocysteine (Sec), the sulfur-to-selenium substituted variant of cysteine (Cys), is the defining entity of selenoproteins. These are naturally expressed in many diverse organisms and constitute a unique class of proteins. As a result of the physicochemical characteristics of selenium when compared with sulfur, Sec is typically more reactive than Cys while participating in similar reactions, and there are also some qualitative differences in the reactivities between the two amino acids. This minireview discusses the types of modifications of Sec in selenoproteins that have thus far been experimentally validated. These modifications include direct covalent binding through the Se atom of Sec to other chalcogen atoms (S, O and Se) as present in redox active molecular motifs, derivatization of Sec via the direct covalent binding to non-chalcogen elements (Ni, Mb, N, Au and C), and the loss of Se from Sec resulting in formation of dehydroalanine. To understand the nature of these Sec modifications is crucial for an understanding of selenoprotein reactivities in biological, physiological and pathophysiological contexts.

Study of the quality and antioxidant properties of tomatoes (Solanum lycopersicum L.) under different postharvest and dehydration conditions

2020 ◽  
Vol 13 (9) ◽  
Author(s):  
María Lorena Luna-Guevara ◽  
Teresita González-Sánchez ◽  
Adriana Delgado-Alvarado ◽  
María Elena Ramos-Cassellis ◽  
José Guillermo Pérez-Luna ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Rural Communities ◽  
Antioxidant Properties ◽  
Titratable Acidity ◽  
Physicochemical Characteristics ◽  
Soluble Solids ◽  
Convective Drying ◽  
Tomato Fruits ◽  
Solanum Lycopersicum L ◽  
Storage Temperatures

Objective: To study the effect of storage temperatures and dehydration conditions (solar and convective drying; SD, CD), on the quality, physicochemical parameters and antioxidant properties of tomato fruits. Methodology: The physicochemical characteristics pH, titratable acidity, soluble solids (°Bx) and color parameters (L*, a* and b*), were evaluated. The lycopene, carotenoids and antioxidant activity percentages retention of tomatoes fruits stored at 7 and 22 ° C for 5 days and subjected to SD (Temperature (T) of 67 °C and luminescence of 685 lum/sqf) and CD (T 70 °C, flow rates 0.5, 1.0 and 1.5 m/s), were analyzed. Results: The fruits reached humidities of 17 and 15% for SD and CD. The parameters pH, °Bx, L*, a*, b* were highest with 22°C and CD (1.5 m/s). The value of the carotenoids was higher in fruits stored at 7 ° C and subjected to CD (1.0 and 1.5 m/s) and SD with values of 83.85, 85.98 and 99.43%, respectively. The CD (0.5 m/s) and SD improved lycopene (94.37 and 95.14%) and the antioxidant activity with values of 73.06 and 97.21%. Implications: The application of solar dehydration depends on luminescence condition; however, it is inexpensive and environmentally friendly alternative. Conclusions: The results derived in a viable alternative for the conservation and commercialization of tomato fruits in rural communities

The Garden as Unfinished Narrative of the Good in C.S. Lewis’ Perelandra

2012 ◽  
Vol 2 (1) ◽  
pp. 49-80
Author(s):  
Evrea Ness-Bergstein
Keyword(s):  
The Novel ◽  
Garden Of Eden ◽  
Adam And Eve ◽  
Dead End ◽  
Growth And Change ◽  
Literary Devices ◽  
Hortus Conclusus

In Lewis’ transposition of Milton’s Paradise to a distant world where Adam and Eve do not succumb to Satan, the structure of Eden is radically different from the enclosed garden familiar to most readers. In the novel Perelandra (1944), C.S. Lewis represents the Garden of Eden as an open and ‘shifting’ place. The new Garden of Eden, with Adam and Eve unfallen, is a place of indeterminate future, excitement, growth, and change, very unlike the static, safe, enclosed Garden—the hortus conclusus of traditional iconography—from which humanity is not just expelled but also, in some sense, escapes. The innovation is not in the theological underpinnings that Lewis claims to share with Milton but in the literary devices that make evil in Perelandra seem boring, dead-end, and repetitive, while goodness is the clear source of change and excitement.

Derwent Moultrie Coleridge's Australian Exile

Romanticism ◽  
2018 ◽  
Vol 24 (1) ◽  
pp. 22-35
Author(s):  
Nicola Healey
Keyword(s):  
Nineteenth Century ◽  
Cambridge University ◽  
Dead End ◽  
Family Home

The literary career and troubled life of Derwent Moultrie Coleridge (1828–80), Derwent Coleridge's eldest son (S. T. Coleridge's first grandson) has been critically overlooked. After a period of alcohol-related, reckless behaviour at Cambridge University, he was exiled to Australia in November 1850, lest he continue to dishonour his father and the Coleridge name. Despite struggling considerably, he quickly became part of an Australian literary circle and he often contributed poems to Sydney newspapers. This essay analyses the most biographical of his poems that was published in the Australian press, ‘The Loafer's Christmas’ (1871) – a hitherto unknown poem – looking, in particular, at the dialogues in which the poem engages with his family, especially S. T. Coleridge's ‘The Rime of the Ancient Mariner’. I also contextualise ‘The Loafer's Christmas’ within nineteenth-century Australian culture. Looking at issues of exile, idleness, addiction, family, home(lessness), and religious redemption, this essay explores the ways in which Derwent Moultrie's exile proved to be both a literary liberation and a dead end, trapping him between times and spaces, real and imaginary. In so doing, I show how the lost life and writings of Derwent Moultrie Coleridge can offer us new perspectives on the Coleridge legacy.

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